Tom Chapin's "This Pretty Planet" awakened Discovery's seven astronauts at 6:35 a.m. Central time today to begin their fourth day of science activities. The song was requested by pilot Steve Lindsey's wife, Diane. Today's primary activity will be deployment at 1:03 p.m. CST this afternoon of the Spartan solar physics satellite, which will fly free of Discovery for two days studying the outer layers of the sun's atmosphere.
Mission Specialist Steve Robinson will use Discovery's robot arm to grapple Spartan from its berth in the payload bay and prepare it for its release. Once it is deployed, Spartan will conduct a programmed pirouette maneuver that will confirm that all of its systems are working normally. Commander Curt Brown then will maneuver Discovery away from the satellite, first to a short distance for a test of a communications link that will permit Spartan ground controllers to make fine pointing adjustments to one of the satellite's science instruments. Brown then will increase Discovery's separation to a distance of about 40 miles in front of Spartan. The satellite will be retrieved by Robinson using the robot arm on Tuesday. Spartan was unable to perform solar science studies last November following problems with its deployment during the STS-87 mission aboard Columbia.
Spartan's two main instruments; the Ultraviolet Coronal Spectrometer and the White Light Coronagraph, will measure atomic temperatures and densities, as well as solar wind velocities in the sun's corona so scientists can better understand the forces that create solar wind, and the impact it has on the electromagnetic environment around the Earth. Solar wind can have major impacts on communications technology on Earth.
Discovery's astronauts also will continue a battery of medical studies as they explore how the human body adapts to the weightless environment of space and how those changes compare with those seen as part of the aging process on Earth.
As part of the Canadian OSTEO experiment, Payload Specialist John Glenn will feed bone cell cultures as part of an evaluation of bone cell activity under microgravity conditions. Glenn will again provide blood samples as part of the Protein Turnover Experiment, which is looking at the balance between the building and breakdown of muscle. He also will work with the Advanced Organic Separations (ADSEP) experiment, which provides the capability to separate and purify biological materials in microgravity; and with the Microencapsulation Electrostatic Processing System (MEPS), which studies the formation of anti-tumor capsules containing two kinds of drugs.
Other research today will include use of the Advanced Gradient Heating Facility (AGHF) for directional solidification and crystal growth, and the Microgravity Glovebox (MGBX) for investigations of colloids, or systems of fine particles suspended in fluid..
At 4:35 p.m. Central time, Brown and Glenn will take part in a news conference with reporters at the Johnson Space Center.
Discovery is orbiting the Earth every 95 minutes at an altitude of about 340 statute miles with all systems operating in excellent condition.
The next STS-95 status report will be issued at approximately 6 p.m. Central time Sunday.